This research proposal deals with the development of a caries prevention method. The approach involves treatment of the enamel surface with selected silylating agents. The intent is to modify the physicochemical properties of the enamel surface, by forming covalently-bound enamel-silyl derivatives, in a way which could protect it from cariogenic attacks. The initial phase of the investigation is focused on determining (a) the nature of surface interactions, and (b) the influence of various factors on the stability of the enamel-silyl derivatives. The analytical tool to be used for this part of the study will be Fourier Transform Infrared (FT-IR) spectroscopy. Subsequently, procedures will be developed to increase the yield of enamel-silyl derivatives, and make feasible the intraoral application of enamel silylation. In the following phase of the study selected silylating agents (existing and new ones to be synthesized) will be tested in vitro with respect to their ability to render to the enamel surface (a) antiplaque properties, and (b) protection from demineralization by acids. Accomplishment of the above objectives would lead to the development of the final two phases of the study which would involve an in vivo investigation with experimental animals, in order to determine: (a) effectiveness in prevention of dental plaque and caries, and (b) toxicity of the selected as most effective silylating agents.